You can’t change those things. That is the level of details which Laminar has intended to implement. But if it’s the Boeing 737-800 that you’re interested in flying, why not give the excellent Zibo Mod a try? It is superior in every way than the default B738 from which it was based: system details, flight model, avionics, FMC, immersion, continuous improvement and so on; except for the lower framerate. And it is free.